Can In-Laws Marry in the Church?

Q: I teach a Bible Study and I ventured into the area of annulments. I was explaining consanguinity as an impediment to marriage. Someone raised a related issue that I could not answer. Deuteronomy 25 presents the Levirate Law, which obliges a brother to marry his deceased brother’s wife, in certain circumstances. The question asked was whether or not the Church allows a brother to marry his deceased brother’s wife today? –Mark

A: In “Can Cousins Marry in the Church?” we looked at the law regarding the marriage of those related by consanguinity, i.e., of persons who are blood relations. Mark’s question, however, refers to the marriage of those who are related not by blood, but by a prior marriage—in other words, to in-laws. Can a widowed man marry his sister-in-law in the Church? Let’s see what canon law has to say about this subject.

The basic concept is addressed in canon 109, which defines affinity. A relationship of affinity arises from a valid marriage, and it pertains to the wife and the blood relatives of her husband, or the husband and the blood relatives of his wife. Let’s say that John Jones and Susan Smith are married. By their marriage, John has become related by affinity to the other members of the Smith family, and Susan is now related by affinity to the other Joneses. If it weren’t for John and Susan’s marriage, Susan and the Joneses, and John and the Smiths, would have no relationship at all.

It’s worth pointing out that the law specifies that affinity arises only from a marriage that is valid in the eyes of the Church. This means that if a marriage has been annulled, there is no question of affinity whatsoever. This is only logical, since a declaration of the nullity of a marriage is a finding that no marriage had ever existed. (See “Marriage and Annulment” for more on this issue.) If a couple were never really married, it follows that they have no in-laws from their marriage!

Affinity is calculated just like consanguinity is, in lines and degrees (cf. c. 109.2). The relationship between a mother-in-law and her son-in-law, or a daughter-in-law and her father-in-law, is said to be in the direct line; while brothers- and sisters-in-law (as well as nieces/nephews, cousins, and even more distant relatives) are related in the collateral line. So what happens if a spouse dies, and the widow or widower subsequently wants to marry an in-law?

The answer, which is actually quite straightforward, is found in canon 1092. Affinity in any degree of the direct line invalidates marriage. This means that a widow may not marry her father-in-law, or her son-in-law; a widower cannot marry his late wife’s widowed mother (his mother-in-law) or his late son’s wife (his daughter-in-law). A marriage of this kind would be invalid.

Note that the code is completely silent about affinity in the collateral line—which means that there is no prohibition at all. It is thus possible to marry a brother- or sister-in-law, or the cousin of one’s deceased spouse. This was not always the case, however: under the 1917 Code of Canon Law, affinity was an impediment to marriage in both the direct line and also certain degrees of the collateral line, which included not only brothers- and sisters-in-law, but also first cousins! The impediment of affinity presumably arose generations ago as one way to avoid excessive intermarriage between two families—which could easily result in complicated blood relationships if there were children from the marriages in question. But as we saw in “Are Women Required to Cover Their Heads in Church?” the old code was abrogated in 1983 by the current Code of Canon Law, so the laws contained in the former code no longer apply.

The Church could make this change in the law because the marriage impediment of affinity is not considered a matter of divine law. The difference between divine law and ecclesiastical law was addressed in greater detail in “Are There Any Limitations on the Power of the Pope?” but in short, the Church lacks the power to change those laws which it believes it received directly from God Himself. To cite an example, the Church can never change the prohibition on marrying one’s own sibling (c. 1078.3), because this is a law that is obviously based in nature, as God intended it! In contrast, the Church could certainly change its deadline for taking recourse against an administrative decree, which is set at ten days (c. 1734.2). This time-limit was not given to us by God, and thus could be lengthened or shortened if the Pope were to determine that such a change was necessary.

Since the impediment of affinity in marriage was not held to be of divine law, Pope John Paul II was free to change it as he saw fit. As we’ve seen, with the promulgation of the 1983 Code of Canon Law, he retained the impediment in the direct line, but abolished it in the collateral line. This wasn’t an arbitrary decision. During the process of revising the new code, in the years preceding its promulgation in 1983, more than one of the experts involved in the process observed that in one particular situation it is entirely appropriate for a widow/widower to marry an in-law: when a spouse dies, and the survivor is left with young children to raise. Returning to our imaginary couple described above, let’s say that John and Susan Jones have young children—and Susan passes away. Susan’s sister Marie is only a couple of years younger, and is not married. Understandably, both John and his children know her rather well. It may seem entirely natural to the entire family if John eventually marries Marie, who then can help to raise her late sister’s children. Since Marie isn’t a complete stranger to the children, they may feel quite comfortable with such a new stepmother. This scenario doesn’t happen every day, but it evidently occurs often enough to have helped to motivate the change in canon law, in order to permit such a marriage.

Before the change in the law took effect, it was still possible for a widowed John Jones to marry his sister-in-law Marie Smith in the Church, if they had first obtained a dispensation from the impediment of affinity from their bishop. This is also true of the impediment in the direct line today. (The concept of dispensation, or the relaxation of a merely ecclesiastical law in a particular case [c. 85], was discussed at greater length in “Marriage between a Catholic and a Non-Catholic.”) If, let’s say, a widowed man wishes to marry his widowed mother-in-law—hardly a common occurrence!—the diocesan bishop can assess the situation and determine whether a dispensation from the impediment of affinity should be granted. Depending on the individual circumstances of the families involved, it might not be inappropriate.

So in answer to Mark’s original question, a Catholic man is indeed allowed to marry his late brother’s wife today, although he is of course under no obligation to do so! The Church continues to evidence concern for marriages between in-laws in some situations, but at the same time it acknowledges that marrying one’s in-law isn’t always a bad thing.

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 1,591 other subscribers

Email Address

About the author

Cathy Caridi, J.C.L., is an American canon lawyer who practices law and teaches in Rome. She founded this website to provide clear answers to canonical questions asked by ordinary Catholics, without employing all the mysterious legalese that canon lawyers know and love.
In the past Cathy has published articles both in scholarly journals and on various popular Catholic websites, including Real Presence Communications and Catholic Exchange.

Canon lawyers are not responsible for the content of canon law. The Supreme Legislator is. Only Pope Francis can change the Code of Canon Law, so if you're not happy with what the law says, please take it up with him.

NOT an ad, just a recommendation!

Catholics who are loyal to the Magisterium often come to Rome and book tours which they discover are led by persons either ignorant of, or even overtly hostile to our Church. Faithful Catholics planning a visit to Rome are encouraged to check out Catholic Custom Tours of Rome, on Facebook and also on the web at www.cctoursofrome.com